A device for connecting an aero-engine with an aircraft pylon is usually called an installation joint which mainly functions to connect the engine and transfer the load of the engine to an aircraft pylon structure.
A pylon is a connection interface between an aero-engine and an airfoil and mainly functions to mount the engine, transfer engine load, provide a pathway for systems such as a fuel pipeline system, environment control system, electrical system and hydraulic system between the engine and the airfoil. The pylon structure should meet the space requirement of the inside system and ensure an excellent force transfer path. To meet the above requirement, as shown in FIG. 1, a pylon 10′ in a conventional configuration is usually designed as a rigid box-shaped structure consisting of an upper beam, a lower beam, a frame having a plurality of vertical stations, and a sidewall which are connected to one another, and assembled with the engine via a front installation joint 20′ and a rear installation joint 30′. The total load of the engine is transferred via the front installation joint and the rear installation joint.
FIG. 2a and FIG. 2b illustrate the front installation joint 20′ and the rear installation joint 30′ of FIG. 1 respectively from another perspective. As shown in FIG. 2a and FIG. 2b in combination with FIG. 1, the front and rear installation joints 20′, 30′ are connected to a front and rear engine connectors of the pylon respectively via four pull-receiving bolts (not shown) engaged in pull-receiving bolt holes 24′ and two shear pins (not shown) engaged in shear-receiving pin holes 42′.
As shown in FIG. 2a in combination with FIG. 1, the front installation joint 20′, at a rear side, is inserted into a main force-bearing box segment of the pylon 10′, and connected to a front end frame, an upper beam, a lower beam and a side web of the front end frame via its bracket 25′. The front installation joint 20′ mainly consists of a left front installation joint 21′, a middle front installation joint 22′ and a right front installation joint 23′. The left and right front installation joints 21′ and 23′ are connected to the engine respectively via two pull-receiving bolts to transfer vertical load; and the middle installation joint 22′ is connected to the engine via two shear pins to transfer a course load and a lateral load.
As shown in FIG. 2b in combination with FIG. 1, the rear installation joint 30′ of the pylon is upwardly connected to the frame of the pylon and downwardly connected to the engine. The rear installation joint 30′ mainly consists of a front section and a rear section, with each section being connected to the engine respectively via two pull-receiving bolts to transfer the vertical load and engine torque, and being connected to the engine via the shear pins to transfer the course load and lateral load.
The pylon in the conventional configuration transmits torque via the rear installation joint 30′. To have an enough long arm of force to transmit torque, the rear installation joint 30′ must have a larger width, which causes the shape of a rear edge of the pylon wider, affecting aerodynamic performance of the aircraft. Besides, the front installation joint 20′ is an individual component independent from the pylon but connected to the pylon, and the whole engine installation structure is heavy and it is difficult to reduce fuel consumption of the engine.